A connector for medical use having a first end also referred to as “upstream end” intended to be connected to a pipe conducting a fluid; and a second end also referred to as “downstream end” intended to cooperate with a device for sampling or injecting said fluid via a connector of male Luer type is known from document EP 1890760. In the following, expressions “upstream end” and “downstream end” will be used regardless of the fluid flow direction.
In practice, the connector has a chamber secured at its base to a fitting forming the upstream end of the actual connector. The free end of the chamber, opposite to the base, is intended to receive, by friction, the tip of a male Luer connector. The flowing of the fluid between the pipe connected to the upstream end of the connector and the end of the male Luer is ensured by means of a needle secured to the body of the fitting. The needle extends in the chamber and emerges into the terminal end of said chamber.
The needle is encased and maintained within the recess of an elastic seal having, across the thickness of its free terminal end, a slit or the like enabling the needle to pass when the elastic seal is compressed in the connected position of the connector.
The elastic seal has a free end tangent to the free end of the chamber and is provided with a ring encircling its terminal portion all the way to the area opposite the lateral hole(s) of the needle.
Further, along a portion of the length of the terminal end of the chamber, the external surface of the elastic seal and/or the internal surface or the thickness of the ring has at least one recess intended to ensure the retreat of the material forming the seal, at the passing of the needle.
In practice, the internal cross-section of the terminal compartment of the chamber may be cylindrical or of female Luer type, that is, with a 6% Luer cone. To ensure the guiding of the elastic seal, the ring portion contained in the central compartment of the chamber has a cylindrical shape.
To ensure the system tightness, that is, the tightening of the elastic seal causing the closing of the slit, the external cross-section of the seal in contact with the ring downstream of the recess of said ring is greater than the corresponding internal cross-section of the ring. However, upstream of the recess(es), the external cross-section of the seal is substantially equal to the internal cross-section of the ring.
Further, the guiding of the seal in the chamber is ensured by the ring only, having all or part of its wall in sliding contact with the corresponding wall of the chamber for the entire duration of the elastic seal motion, from its relaxed position to its compressed position. Due to the plastic nature of the materials used, there is only a minimum friction force between the chamber and the ring.
However, although it is quite satisfactory, the connector which has just been described can further be improved.
First, since the ring has a cylindrical shape and the end of the chamber has a Luer shape, there necessarily remains a space between the ring and the internal wall of the free end of the chamber (see FIG. 2). Small though this space may be, contamination risks remain possible.
Further, since the contact surface area between the Luer cone of the sampling device or the like and the connector is formed by the free end of the ring only, the tightness between the two elements is not optimal, the two surfaces being made of rigid plastic material.
Finally, the discontinuous configuration of the free end of the connector, which alternates, from the center to the periphery, independent materials of different nature (the resilient portion, the ring, a space, and finally the chamber wall) does not enable either to properly decontaminate the end of the connector after disconnection.
Document WO96/13331 described a connector for medical use comprising a fitting secured to a chamber and provided at its center with a needle comprising at least one lateral hole. The needle is encased, at least in its terminal portion, in the recess of an elastic seal. The elastic seal has a slit across the thickness of its free end, and is provided with a ring encircling its terminal portion, upstream of the needle hole, in disconnected position of the connector. The peripheral rim of the elastic seal enables to ensure a sliding motion and a proper alignment of the elastic seal on insertion of the sampling device or the like in the cylindrical portion of the connector. It should particularly be specified that this peripheral rim does not change the tightness properties of said connector.